The present invention relates to power auger machines and, more particularly, to power auger machines having bearing shields interposed between rotating and nonrotating components.
Power auger machines, such as the auger shredder disclosed in Koenig U.S. Pat. No. 4,253,615, typically include a frame forming a grinding chamber with an upwardlyopening inlet hopper and either a side or bottom discharge opening. A rear wall of the grinding chamber supports an auger, mounted on a support disc, which is rotatably driven by a motor mounted within an enclosed housing. The wall includes a central opening through which a bearing plate extends. Materials to be processed by the rotating auger are deposited downwardly through the inlet opening and are ground, crushed and pumped outwardly through the discharge opening.
Frequently, hazardous, radioactive or highly corrosive materials are processed by such an auger and can contaminate or foul the main bearing or motor housing if the material works its way behind the wall on which it is mounted through the gap formed between the rotating auger support disc and the wall. Accordingly, there is a need for a seal or shield which prevents the contaminants from working their way between the rotating and nonrotating components of the power auger and fouling or contaminating bearings and other components of the device.
A similar problem exists with mining machinery, which includes powered augers extending outwardly from enclosed motor housings. Typically, such auger devices are operated in hazardous environments which contain fine particles of rock or metal which may corrode or attack the main support bearings for the power augers.
Solutions to this problem include the seal lubrication device disclosed in Hufford et al. U.S. Pat. No. 4,804,194. That patent discloses a seal lubrication mechanism which is employed between a rotating shaft and an outer, cylindrical shaft housing. A block is secured to the rotating shaft and supports a spring which urges a seal ring, which rotates with the shaft, against a stationary seal ring. An annular baffle defines a channel for lubricant to flow to the interface between the rotating and nonrotating seal rings.
A disadvantage with such structure is that it requires spring elements in order to urge the rotating and nonrotating seal rings together. Such spring structures may provide uneven support in instances of shock loading of the shaft.
Accordingly, there is a need for a power auger machine having a bearing shield between the rotating and nonrotating components which is capable of preventing contaminants from working inwardly between the rotating and nonrotating components and fouling or corroding the main bearings and motor structure. In addition, there is a need for such a bearing shield to resist thrust and shock loads and to be easily repairable in the field.